Front end loaders for refuse collection traditionally have two arms, one on each side of the chassis. The arms are generally pivotally attached at the lower front corners of the body and connected together by an arm cross-shaft at the proximal end of the front end loader, nearest the vehicle. The arms are also generally connected together by another member at the distal end of the front end loader, furthest from the vehicle body, where the mechanism for engaging and lifting a refuse container is located. The arm cross-shaft is generally journalled in bearings, one on each side of the body.
Forks extend from the distal ends of the arms, and are pivotally connected on a fork cross-shaft. The forks engage in the pockets of a refuse container. The container is then lifted when the arms and the forks are hydraulically actuated to rotate the container for dumping the contents of the container into the vehicle body. The arms are typically rotated by two arm cylinders, one on each side of the body. While forks are specifically employed in the present design, other similar engagement and lifting could also be employed in connection with the present clamp connector.
Since there is a potential for unequal loading on the arms due to unequal loading in the container or other similar conditions, the arms are typically fixed to the arm cross-shaft so that the arm cross-shaft can transmit torque from the lighter loaded arm to the heavier loaded arm. The fixing of the arms to the cross-shaft also assures that the arms are raised and lowered together. This fixing is traditionally accomplished by welding the arms to the arm cross-shaft or by bolting the arms to the arm cross-shaft using a flange extending from each arm and a flange extending from each of the opposite ends of the arm cross-shaft.
The traditional approach to fixedly attaching the arms to the arm cross-shaft has the following disadvantages:
(1) Welding the arms to the arm cross-shaft makes arm replacement extremely difficult because the entire assembly must be removed or the welds must be burned off the shaft, a time-consuming process likely to result in damage to the cross-shaft. PA1 (2) The attachment of the arms to the cross-shaft by flanges makes arm replacement easier, but the flange design is heavy and costly. PA1 (3) The arm cross-shaft is loaded in bending and torsion, and as a result, cross-shaft breakage is not uncommon due to stress raisers caused by the flange welding to the shaft or the arm welding to the shaft. PA1 (4) For ease in servicing, split bearings and bushings are employed. This is an expensive and heavy design. PA1 (a) a pair of arm members pivotally attached at their proximal ends to the body of the front end loading vehicle, PA1 (b) an arm cross-shaft extending between the arm members at the proximal end of the arm members, and PA1 (c) a pair of clamp connectors extending from the arm members, as described above.
Past efforts to attach the arms of a front end loader to the arm cross-shaft by a clamping method have been unsuccessful because insufficiently uniform clamping force around the cross-shaft was available to resist the tendency of the arm to slip on the shaft during the transmission of torque, as described above.